28111005 has 48 divisors (see below), whose sum is σ = 54316080. Its totient is φ = 13353984.

The previous prime is 28111003. The next prime is 28111019. The reversal of 28111005 is 50011182.

It can be written as a sum of positive squares in 8 ways, for example, as 3250809 + 24860196 = 1803^2 + 4986^2 .

It is not a de Polignac number, because 28111005 - 2¹ = 28111003 is a prime.

It is a super-2 number, since 2×28111005² = 1580457204220050, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28111001) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 16137 + ... + 17793.

It is an arithmetic number, because the mean of its divisors is an integer number (1131585).

Almost surely, 2^28111005 is an apocalyptic number.

It is an amenable number.

28111005 is a deficient number, since it is larger than the sum of its proper divisors (26205075).

28111005 is a wasteful number, since it uses less digits than its factorization.

28111005 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1710 (or 1707 counting only the distinct ones).

The product of its (nonzero) digits is 80, while the sum is 18.

The square root of 28111005 is about 5301.9812334636. The cubic root of 28111005 is about 304.0596496812.

Adding to 28111005 its reverse (50011182), we get a palindrome (78122187).

The spelling of 28111005 in words is "twenty-eight million, one hundred eleven thousand, five".